Cooling system



G. S. BLANKENHORN.

COOLING SYSTEM.

APPLICATION FILED FEB- 5, 1917.

Patented Apr. 19, 1921.

controlled by the temperature of the cool- UNITED STATE-S PATENT OFFICE.

GEORGE S. BLANKENHORN, OF MILWAUKEE, WISCONSIN, ASSIGN'OR TO ALLIS-CHALMERS MANUFACTURING COMPANY, OF MILWAUKEE, WISCONSIN, A

CORPORATION OF DELAWARE.-

COOLING SYSTEM.

Specification of Letters Patent.

Patented Apr. 19, 1921.

Application filed February 5, 1917. Serial No. 147,243.

To all whom it may concern Be it known that I, Gnonon S. BLANKEN- HORN,a citizen of the United States, residing at Milwaukee, in the county ofMilwaukee and State of \Visconsim-have invented a certain new and usefulImprovement in Cooling Systems, of which the following is aspecification.

This invention relates to improvements in cooling systems for engines,being especially applicable to cooling systems for the engines of motorvehicles.

An object of the invention is to provide a cooling system which issimple in construction and efiicient in operation. Another object is toprovide a thermostatic control for the air flowing past the radiator.One of the more specific objects is to provide means dependent upon thetemperature of the water in an engine cooling system, for controllingthe flow of cooling air, past the radiator of the system.

It has heretofore been proposed to regulate the temperature of thecooling water in the cooling system of an internal combustion engine bydetermining the flow of cooling water through the system, suchdetermination being effected by a mechanism ing water. In this priorsystem the quantity of cooling air passing the radiator was maintainedconstant for a given speed of the engine,-thereby causing the flow ofmore air than necessary past the radiator, at certain times. This priorsystem also failed to provide means for preventing ready freezing of thewater in the radiator.

The improved system forming the sub ject of the present invention,provides thermostatic means for controlling the quantity of air flowingpast the radiator, without affecting the flow of liquid through thecooling system. The system of the present invention also provides meansfor effectively preventing excessive rise in temperature and forpreventing ready freezing of thewater in the radiator.

While the invention is disclosed as applied to an engine in which theflow of air past the-radiator is induced by fan'means, it is to be notedthat such fan means. are not essentialand that impositive flow inductionmeans may be utilized.

A clear conception of an embodiment of the invention may be had byreferring to the drawing accompanying and forming a part of thisspecification in which like reference characters designate the same orsimilar parts in the various views.

Figure 1 is a fragmentary side elevation, partly in section, of aninternal combustion engine cooling system.

Fig. 2 is an enlarged fragmentary side elevation, partly in section, ofa modified form of clutch mechanism.

The internal combustion engine cooling system disclosed in Fig. 1comprises a jacket of ordinary construction formed as conduit meanslocated adjacent the cylinders 1, a casing 2 forming a water chambercommunicating with the upper end of the jacket, a pipe 3 connecting thecasing 2 with the upper chamberof the radiator 4, a plurality of tubesor other conduit means connecting the upper and lower chambers of theradiator 4, a pipe 5 connecting the lower chamber of the radiator 4 withthe pump, 6, the pump 6 or similar flow-producing means of ordinaryconstruction, and a pipe 7 connecting the dischargeof the pump 6 withthe cylinder jacket.

The radiator 4 is provided with one or more through passagescommunicating with acasing 10 within which is located a rotary fan 9.The fan 9 is rotatably mounted upon the stationary stub shaft 21 whichengages the bore of the fan hub 20. The fan 9, while rotating, draws airthrough the radiator\fl, the rate offlow of the air being proportionalto the speed of rotation of the fan. Upon the shaft 21 adjacent the fanhub 20, is located a. fan clutch pulley 12. The pulley 12 is rotatablyconnected by means of a belt 14 with the main fan pulley 13 which isdriven by the engine, in the usual manner.

A thermostat comprising a rod 8 formed of suitable metal such as brass,and having its one end fixed to the casing 2, is mounted within and issurrounded by the liquid in the casing 2. The rod 8 penetrates theeasing 2 through a stuffing box 18 and has its end provided. with anelongated slot 19 which engages a. pin secured to the mid portion of thelever 11. A hellcal compression spring 16 embraces the rod 8 and has itsopposite ends in engagement respectively with a collar 17 adjustablysecured to the rod 8, and with the lever 11,

The lever 11 has its upper end pivoted upon a suitable bracket fixed tothe pipe 3, and has its lower extremity in engagement with an. annularrecess 15 in the fan pulley 12. The mounting and arrangement of thelever 11 is .such that as it is moved in a clockwise direction, thelower end moves the pulley 12 toward the left and produces frictionalengagement between the pulley 12 and the hub 20 of the fan 9, therebycausing the fan to rotate and the speed of rotation being proportionalto the engaging pressure.

In the modified form of clutch disclosed in Fi 2, the fan 22 ihas'a hub23 and is rotata ly mounted upon the stub shaft 21. The hub 23 hasseveral pawl members 25 pivotally mounted thereon and normally held inthe position shown by means of helical compression springs 27. The fanpulley 24 is provided with an end surface adapted for frictionalengagement with the fan hub 23, and has a series of notches 26 formedaround the interior thereof. As the pulley 24 is shifted into engagementwith the fan hub 23 by means of the thermostat and the lever 11, thepawl members 25 move outwardly, due to the action of centrifugal forcesthereon, and eventually engage the notches 26. With the pawl members 25in engagement with the pulley notches 26, the fan 22 and pulle 24 rotateat the same speed, this speed eing proportional to the speed of theengine.

During the normal operation of the en gme, the cooling liquid, whichordinarily is water, is caused to circulate through the jacket of thecylinders 1 and through the radiator 4 by means of the pump 6 oranyother means ordinarily employed to produce such circulation. The waterafterbe- 1ng heated in the cylinder jacket enters the casing 2 fromwhich it flows to the radiator 4 through the pipe 3. After being cooled1n the radiator, the water is withdrawn through the pipe 5 and isdelivered back to the cyllnder jacket or to a storage tank by means ofthepump 6.

{is the temperature of the water in the caslng 2 rises, the rod 7expands, this expansion acting through the collar 17 and spring 16 andcausing the lever 11 to swing in a clockwise direction about itsstationary upper pivot. The swinging of the lever 11 moves the rotatingfan pulley 12 bodily toward the left and causes the pulley hub to engagethe fan hub 20 and to rotate the fan 9 more or less in accordance withthe engaging pressure. After the limit of travel of the lever 11 andpulley 12 has been attained, excess expansion of the rod 8 iscompensated for by the spring 16 and opening 19, the opening 19permitting relative movement of the rod 8 and lever 11 duringcompression of the spring. It will thus be noted that the quantity ofair flowing through the radiator, which quantity is proportional to thespeed of the fan 9, is controlled by the temperature of the water in thecooling system through the medium of the thermostat. If the water in thecooling system becomes undesirably cool, the lever 11 will disengage thefan hub 20 and pulley 12, thereby eliminating the induced flow of airpast the radiator. By eliminating the flow of air past the radiator,ready freezing of the water is prevented.

In the modified clutch mechanism dis-f closed in Fig. 2, the speed ofthe fan will be proportional to the temperature of the cooling wateronly during the time that the pawl members 25 are out of engagement withthe notches 26. When the pawl members 25 engage the notches 26 the speedof the fan is proportional to the speed of the en ine.

It is to be noted that while the thermostat is disclosed as dependentupon the temperature of the cooling water, it may be desirable to havethe operation of the thermo-' stat dependent upon the atmospheric tem--perature, such modification being within the contemplated scope of thepresent invention.

It should be understood that it is not desired to be limited to theexact details of construction herein shown and described, for obviousmodifications may occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent In' an enginecooling system, conduit means adjacent the engine providing a passagefor cooling water, a radiator connected with said conduit means, a fanfor inducing a flow of air ast said radiator, a thermostat operable yvariations in temperature of the cooling water, a friction clutchoperable by said thermostat to vary the speed of said fan, and means forpositively connecting said fan to the engine upon attainment of apredetermined speed.

In testimony whereof, the signature of the inventor is affixed hereto. I

GEORGE S. BLANKENHORN.

